root

n.

"underground part of a plant," late Old English rot, from a Scandinavian source akin to Old Norse rot "root," figuratively "cause, origin," from Proto-Germanic *wrot (cf. Old English wyrt "root, herb, plant," Old High German wurz, German Wurz "a plant," Gothic waurts "a root," with characteristic Scandinavian loss of -w- before -r-), from PIE *wrad- (see radish (n.), and cf. wort). The usual Old English words for "root" were wyrttruma and wyrtwala.

Figurative use is from c.1200. Of teeth, hair, etc., from early 13c. Mathematical sense is from 1550s. Philological sense from 1520s. Slang meaning "penis" is recorded from 1846. In U.S. black use, "a spell effected by magical properties of roots," 1935. To take root is from 1530s. Root beer, made from the extracts of various roots, first recorded 1841, American English; root doctor is from 1821. Root cap is from 1875.

Associated with the verb sense of root (n.). Extended sense of "poke about, pry" first recorded 1831. Phrase root hog or die "work or fail" first attested 1834, American English (in works of Davey Crockett, who noted it as an "old saying"). Reduplicated form rootin' tootin' "noisy, rambunctious" is recorded from 1875.

A plant part that usually grows underground, secures the plant in place, absorbs minerals and water, and stores food manufactured by leaves and other plant parts. Roots grow in a root system. Eudicots and magnoliids have a central, longer, and larger taproot with many narrower lateral roots branching off, while monocots have a mass of threadlike fibrous roots, which are roughly the same length and remain close to the surface of the soil. In vascular plants, roots usually consist of a central cylinder of vascular tissue, surrounded by the pericycle and endodermis, then a thick layer of cortex, and finally an outer epidermis or (in woody plants) periderm. Only finer roots (known as feeder roots) actively take up water and minerals, generally in the uppermost meter of soil. These roots absorb minerals primarily through small epidermal structures known as root hairs. In certain plants, adventitious roots grow out from the stem above ground as aerial roots or prop roots, bending down into the soil, to facilitate the exchange of gases or increase support. Certain plants (such as the carrot and beet) have fleshy storage roots with abundant parenchyma in their vascular tissues. See also fibrous root, taproot.

Any of various other plant parts that grow underground, especially an underground stem such as a corm, rhizome, or tuber.

The part of a tooth that is embedded in the jaw and not covered by enamel.

Mathematics

A number that, when multiplied by itself a given number of times, produces a specified number. For example, since 2 × 2 × 2 × 2 = 16, 2 is a fourth root of 16.

A solution to an equation. For example, a root of the equation x2 - 4 = 0 is 2, since 22 - 4 = 0.

Roots definition

(1976) A Pulitzer Prize–winning novel by the African-American author Alex Haley, later made into a popular television drama. It traces a black American man's heritage to Africa, where his ancestors had been captured and sold as slaves.

root definition

In biology, the part of a plant that grows downward and holds the plant in place, absorbs water and minerals from the soil, and often stores food. The main root of a plant is called the primary root; others are called secondary roots. The hard tip is called the root cap, which protects the growing cells behind it. Root hairs increase the root's absorbing surface.

root definition

The part of a tooth below the gum. The root anchors the tooth to the jawbone.